Along with those two over-experienced Genins are their clan symbols. You might have your own Hidden Leaf Village vest and headband, but you can't just go out and about wearing that.
They're decorated with the red Akatsuki clouds and Itachi's Konoha headband. They're comfy and stretchy and they're a subtle way to show love to your favorite anime. They're crew length so you can show them off or hide them under long pants. The ninja himself decorates the front ankle of each sock.